Mesoscale Discussion 1607

Issued

Aug 26, 2021, 9:40 AM CDT (14:40 UTC)

Expired

Aug 26, 2021, 11:15 AM CDT

In force

95 min

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch unlikely

Chance of a watch

20%

The Des Moines radar (KDMX), 19 km from the middle of the area, began a volume at 14:40 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

391 
ACUS11 KWNS 261441
SWOMCD
SPC MCD 261440 
IAZ000-MOZ000-261615-

Mesoscale Discussion 1607
NWS Storm Prediction Center Norman OK
0940 AM CDT Thu Aug 26 2021

Areas affected...Central/southern IA into far northern MO

Concerning...Severe potential...Watch unlikely 

Valid 261440Z - 261615Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated damaging wind threat will continue through the
morning with ongoing MCS.

DISCUSSION...A long-lived MCS is moving across central IA at 1430Z.
This system is being supported by steep midlevel lapse rates,
low-level warm advection, and modestly enhanced deep-layer shear.
The system has remained largely sub-severe thus far, with
substantial MLCINH and the lack of a stronger surface cold pool
limiting the potential for stronger wind gusts at the surface. 

If the system can be sustained into the late morning/early
afternoon, the damaging wind threat may increase in conjunction with
steepening low-level lapse rates. However, the VWP from the KDMX
remains lackluster, with weaker low/midlevel flow compared to areas
to the north and west, and the system may begin outrunning the
favorable warm-advection regime that remains focused to the west.
Deep-layer shear also weakens with eastward extent, so some
weakening of the system appears likely unless a stronger cold pool
can be established. The system may tend to propagate more
southeastward with time into the stronger buoyancy, potentially
posing a localized damaging wind threat into parts of southern IA
and far northern MO. Watch issuance remains unlikely in the short
term, unless an uptick in convective organization and/or surface
wind gusts is observed.

..Dean/Dial.. 08/26/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...DVN...DMX...EAX...OAX...

LAT...LON   42549413 42589399 42539331 42379202 41879202 41249228
            40369267 40389428 40509482 40739525 40969494 41549459
            41749449 42549413

Mesoscale Discussions in Iowa, 2021Mesoscale Discussions in Missouri, 2021Every mesoscale discussion in 2021

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.